Kinetics Flashcards
Describe a chemical reaction in terms of collision theory
Reactions occur when reactant particles collide with sufficient energy called activation energy
Define the term activation energy
The minimum energy needed for a reaction to occur and a collision to be successful
Explain why most collisions between particles do not result in a
chemical reaction
The energy of reactant particles is distributed with very few having energy greater than or equal to activation energy
Explain why the Maxwell-Boltzman graph starts at the origin
No particles have zero kinetic energy
Explain why a small increase in temperature has a significant increase in the rate of reaction
At higher temperature significantly more particles have energy greater than or equal to the activation energy. More successful collisions per unit time
Define the term rate of reaction
The change in the amount of reactant or product per unit time
Explain how the reaction between hydrochloric acid and sodium
thiosulfate can be monitored
The reaction produces a sulfur precipitate. Time how long it takes for the precipitate to obscure a cross. Rate = 1 / time
Explain the the reaction between hydrochloric acid and sodium
thiosulfate should only be carried out on a small scale
Toxic sulfur dioxide is a product
Explain how increasing concentration affects the rate of a chemical
reaction
As concentration increases there are more reactant particles per unit volume, therefore more successful collisions per unit time
Explain how increasing pressure affects the rate of a chemical
reaction
As pressure increases there are more reactant particles per unit volume, therefore more successful collisions per unit time
Define the term catalyst
A substance that increases the rate of a chemical reaction without being used up or permanently changed itself
Explain how a catalyst works
Provides an alternative reaction pathway with a lower activation energy. More particles have energy greater than or equal to the activation energy
How would the Maxwell-Boltzman distribution would change with an increase in temperature?
it would shift to the right, more molecules would have activation energy
How would the Maxwell-Boltzman distribution would change with an increase in concentration?
it would shift to the right, more molecules per unit volume leads to more successful collisions per unit time
Explain how the reaction between hydrochloric acid and sodium
thiosulfate can be monitored
The reaction produces a sulfur precipitate. Time how long it takes for the precipitate to
obscure a cross. Rate = 1 / time
